Cosmetic containers, by nature, must be readily portable so as to be carried by the consumer. For instance, cosmetic containers are frequently carried in a purse or packed within a suitcase for travel. The containers must, therefore, be durable and remain closed so as to withstand significant shifting and possible impact. This is particularly true for lipstick containers which are relatively small, frequently haphazardly placed, and often subjected to significant jarring. If the cover of the cosmetic container is easily dislodged from the shell base, it may be unintentionally released, causing the lipstick or other cosmetic contained therein to become damaged; not to mention damage to the purse or other case holding the cosmetic container. It is, therefore, important for the cosmetic container cover to be securely retained upon the shell base to prevent axial movement of the cover relative to the shell base to avoid accidental removal of the cover during transport of the container.
Another problem associated with cosmetic containers, including lipstick containers, is that even if the cover of the container remains intact with the shell base, the cosmetic contained therein may be unintentionally extended from within the shell base. This results in accidental contact of the cosmetic with the inner surface of the cover, resulting in damage to the cosmetic contained therein. Thus, it is important to prevent relative rotational movement between the shell base and the cover to protect the integrity of the cosmetic within the container.
Prior art attempts to provide containers having locking arrangements for mating the cover and shell base have not adequately addressed the aforementioned problems. For instance, several attempts provide positive retention of the cover on the shell base, but do so in a manner which is structurally complicated and therefore relatively expensive to manufacture. For example, U.S. Pat. No. 5,160,057 to Fitjer is directed to a cosmetic container, such as for mascara, wherein a locking arrangement is provided to prevent further rotational movement of the threaded closure cap relative to the base. The cosmetic container includes a base element having a square cross-section and a threaded neck and a threaded closure cap. A locking arrangement is provided which includes two stop shoulders and two stop returns mounted on the base element and two stop and catch protrusions extending inwardly from the interior surface of the closure cap. Accordingly, in use, the screw closure cap is threaded upon the cosmetic container base element wherein the stop catch protrusion rides over the return stop until abutting the stop shoulder to prevent further rotational movement. This arrangement, however, requires threaded members which must be accurately manufactured.
U.S. Pat. No. 2,071,265 to Schmidt is directed to a metal container having a body portion and a cover which does not require threaded members. The metal container according to this patent, however, is complex in that two different locking arrangements are required to prevent both rotational and axial movement of the container cover relative to the body portion. Axial movement is limited by the locking arrangement including a locking lug extending radially outwardly from the body portion and an inwardly extending locking lug of the container cover. Rotational movement is limited by an inwardly extending protrusion of the cover which mates with recesses of the locking lugs. Thus, a complicated structure is disclosed wherein axial and rotational movement of the cover relative to the base requires two distinct locking arrangements.